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8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
1/24
Thomas Jefferson NationalAccelerator Facility
Shedding FEL Light on Dark Mattera simple experimentalist's view of the LIPSS
experiment
Kevin Beard for the LIPSS collaboration
FEL Users Group Meeting
May 16, 2007
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
2/24
Thomas Jefferson NationalAccelerator Facility
A. Afanasev, C. Long, K.W. McFarlane, R. Ramdon,
and H. Brown (Hampton University)
K. Beard, J. Boyce, G. Biallas, and M. Shinn
(Jefferson Lab)
O.K. Baker and M. Minarni (Yale University)
LIght Pseudoscalar or Scalar Search
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
3/24
Thomas Jefferson NationalAccelerator Facility
A very brief history of dark matter...
M51
1933 Zwicky found that therotational speed of stars requiresmuch more mass than can be seen
1823 Olbers asked why the sky isdark at night
2006 NASA reports gravitationallensing from dark matter
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
4/24
Thomas Jefferson NationalAccelerator Facility
what might dark matter be?
baryonic matter -
very dim stars (MACHOs)
non-baryonic matter
hot dark matter ultra-relativistic (, ...)
warm dark matter relativistic
cold dark matter non-relativistic (WIMPs, axions,...)
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
5/24
Thomas Jefferson NationalAccelerator Facility
Many experiments looked for colddark matter......
PVLAS thinks theysaw something !
courtesy O.K.Baker
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
6/24
Thomas Jefferson NationalAccelerator Facility
courtesy O.K.Baker
Axion searches to date
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
7/24
Thomas Jefferson NationalAccelerator Facility
Axion and `Strong CP Problem
Peccei, Quin (1977); S. Weinberg (1978); F. Wilczek(1978)
courtesy A.Afanasev
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
8/24
Thomas Jefferson NationalAccelerator Facility
PVLAS experiment
courtesy of PVLAS:
http://www.ts.infn.it/physics/experiments/pvlas/
ellipticity plane to ellipticalpolarizaton
dichroism rotation of
polarization
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
9/24
Thomas Jefferson NationalAccelerator Facility
light shining through a wall
opaque
wall
light in light out
dark matterparticle
4 42
2
sin( /4 )
2 /4
b
b b
m LBL W R A
M m L
=
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
10/24
Thomas Jefferson NationalAccelerator Facility
BFRT* regeneration expt.
For (identical) magnets lengthL and fieldB, photon energy ,power W, efficiency , and detector sensitivityA, the rateR is:
4 42
2
sin( / 4 )
2 / 4
=
b
b b
B L m L W R A
M m L
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
11/24
Thomas Jefferson NationalAccelerator Facility
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
12/24
Thomas Jefferson NationalAccelerator Facility
LIPSS apparatus.
Brewster windows
935
nm
isolated vacuumsystems
particle?
regenerated
light
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
13/24
Thomas Jefferson NationalAccelerator Facility
details of LIPSS layout (not to scale)
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
14/24
Thomas Jefferson NationalAccelerator Facility
.
Detector optics
Spec10:400BR-LNcamera
lensmirror
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
15/24
Thomas Jefferson NationalAccelerator Facility
What our camera sees...
1340 x 400 = 536000 (20 x 20 m) pixels
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
16/24
Thomas Jefferson NationalAccelerator Facility
#pixels
readoutnoise
dark current
cosmicrays,etc
1 second ADC counts/pixel
2 hour ADC counts/pixel
1340 x 400 = 536000 (20 x 20 m) pixels
bi i i i t t
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
17/24
Thomas Jefferson NationalAccelerator Facility
binning is important
1 X 1 5 X 5
1mm X 1mm regionbinning canbe done on chip beforereadout to minimize noise,but one must choose the binning wisely to optimize the signal
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
18/24
Thomas Jefferson NationalAccelerator Facility
actual power delivered to the LIPSS
dump over 5 days
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
19/24
Thomas Jefferson NationalAccelerator Facility
The beam spot driftedand had to be adjusted
using picomotors everyfew minutes. The spotswere logged to VHS
tape.
The picomotor control systemsometimes moved mirrors on
its own; this is an example ofdamage done by the laser.The beam also damaged &
vented our vacuum system the loss of vacuum wasn'timmediately noticed.
lessons learned...
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
20/24
Thomas Jefferson NationalAccelerator Facility
If you're looking for dark matter,
don't forget to turn off the lights....
temporary very high dark current area on CCD
Not sensitive enough yet to see a signal at the level
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
21/24
Thomas Jefferson NationalAccelerator Facility
all anomaly-free pixels
near region-of-interest
region-of-interest
Not sensitive enough yet to see a signal at the levelexpected on the basis of the PVLAS result
R C ifi
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
22/24
Thomas Jefferson NationalAccelerator Facility 22
Run C specifics
Run C was the first run with adequate monitoring Aquired a good set of data with polarization || to magnetic
field; need a similar set with the polarization to the
magnetic field ~12 MJ of photons were delivered in 12 good 2-hour
runs
The only detectable sources of uncertainty were readnoise and dark current.
Our task is to get to a sensitivity that would enable thePVLAS boson hypothesis to be definitively confirmed orrejected .
courtesy of K.McFarlane
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
23/24
Thomas Jefferson NationalAccelerator Facility 23
Preliminary result for Run C
The preliminary 3-sigma upper limit excludes
boson masses above 1.55 meV.
F t Pl
8/3/2019 Kevin Beard- Shedding FEL Light on Dark Matter: a simple experimentalist's view of the LIPSS experiment
24/24
Thomas Jefferson NationalAccelerator Facility
Future PlansRun again with more power(~1 kW) usingimproved mirrors as soon as possible; take moredata in both pseudoscalar () and scalar ()configurations
Investigate other improvements or follow-onexperiments
Continue the quantum efficiency and uniformitymeasurements on the camera
Complete a thorough statistical treatment of thedata.